Scattered on the sandy bottom about 11 feet deep near Biscayne National Park’s Elliott Key are numerous ceramic shards guarded by schools of gray snapper and grunts. The dusky white and bile green remnants of dinner plates and tea cups don’t look like much and they aren’t worth any money, even to television’s Pawn Stars. But those artifacts and some ancient burned timbers surrounding them have considerable cultural value as living snapshots of a long-ago, unsolved maritime mystery.

Chuck Lawson, archeologist and cultural resources manager at the park for the past two years, would love to identify the ship that carried all that china and find out where it was going and why it sank. But it doesn’t help that divers have been plundering the wreckage illegally for years. And that site, nicknamed “English China,” is one of more than 70 shipwrecks and artifact piles scattered throughout park waters that have been dug up, dredged and pillaged before their origins could be determined.

“Most of them will stay that way forever because people stole things off them in the 1960s and ’70s so you can’t tell who they were, where they were going, or what was on them,” Lawson said.

He’s a bit more optimistic about the English China site because of the large number of ceramic shards found there. The crockery remnants have been positively identified as pieces made by England’s Staffordshire pottery sometime between 1765 and 1770. Also found were several mysterious unglazed figurines not made of the same material. Lawson says they were carried on a wooden sailing vessel about 65 feet long that may have caught fire and sank, based on burned timbers from the bowels of the ship.

A couple weeks ago, Lawson and colleague Nicole Bucchino from the Florida Public Archeology Network dived to inspect the site. To their dismay, they found a sign Lawson had posted warning divers that disturbing the wreck could result in heavy fines and jail time had been propped up on coral rocks to create an illegal casita structure designed to attract lobsters. The improvised aggregation device had worked well; nearly two dozen pairs of bug antennae stuck out from beneath the sign.

Lawson and Bucchino scared the crustaceans away using a boat hook, then removed the coral rocks and placed the sign flat on the bottom.

Lawson couldn’t conceal his disgust.

“Even if you think shipwrecks belong to everybody and you’re unaware of archeological protection laws, there’s no way you should be destroying the environment,” he said.

Lawson is actively working on another maritime mystery in the park — the “Soldier Key wreck,” about a foot deep on a grass flat near the island for which it is named.

The timbers and ballast stones were discovered by two local fishermen in the 1970s, then excavated in the early 1980s by former University of Miami anthropology professor John Hall. Hall collected some artifacts, but they were lost. He kept no records of his findings, and did not replace the ballast stones that covered the remains of what’s believed to be an early 19th century wooden sailing vessel. Hurricane Andrew carried away big pieces of the ship in 1992.

Earlier this summer, Lawson and a team from George Washington University, University of Miami, University of West Florida and the National Park Service’s Southeastern Archeological Center spent 2½ weeks shoring up the site. They used an induction dredge to suck up sand covering the timbers and replaced the ballast stones to stabilize the wreckage, which was sprinkled with a large quantity of allspice.

“A big ship coming from Jamaica which has allspice — probably English — got hit by a hurricane,” Lawson mused. “We’ll have to look at old insurance records. Eventually we’ll know what region of the world it was built in because of the wood.”

Biscayne National Park doesn’t publish GPS coordinates for the English China or Soldier Key wreck sites in order to avoid further disturbance. But it established a shipwreck heritage trail several years ago with GPS coordinates and historical information for six sites that can be accessed by scuba divers and snorkelers visiting the park by boat ( http://www.nps.gov/bisc/historyculture/maritime-heritage-trail.htm.)

Artifacts recovered from the English China site will be displayed in the park visitor center beginning in early fall.

Lawson would like visitors to immerse themselves in the park’s rich maritime history, while leaving historical resources intact for others to appreciate.

“They belong to everybody. The things that are there tell stories that are important — not just to Miami or South Florida’s history, but the whole world’s heritage,” Lawson said. “The artifact you take, then another one is taken — that heritage is lost. These sites as whole units may tell the truth about the past.”